Spell hit
Spell hit is a combat attribute that increases a caster's chance to hit with spells. Spell hit is primarily obtained from talents or gear that has spell hit rating. The more spell hit gear a caster has the lower the chance the casters spells will miss (i.e. an enemy resist the spells). This chance to hit is capped at 99%, therefore there is always be at least a 1% chance to miss with spells (i.e. 1% chance the enemy will resist spells). Base chance to hit is based only on level difference between the caster and the target. A spell that fails to hit is shown as a resist, though this is different than the spell resistance mechanic. Spell hit rating is part of the combat rating system that was introduced with Patch 2.0 and the Burning Crusade expansion. Each point of spell hit rating increases chance to hit with spells by a percentage. Like other combat ratings, the exact percentage per point is based on the player's level, decreasing as level increases. Other than spell hit rating, a caster can increase chance to hit with spells with talents, depending on class. How spell hit chance is calculated The spell hit mechanic has been confirmed by Blizzard CM Eyonix. . Base chance to hit is based on level difference between caster and target, starting at 96% for even levels, and going up or down from there, capping at a maximum 99%. Furthermore, the chance to hit is different for mobs (PvE) and player (PvP) targets. For example, a level 70 caster attacking a level 73 mob will have a 83% chance to hit with spells in PvE. Furthermore, a level 70 caster attacking a level 74 or higher mob decreases by an additional 11% per level in PvE, and by 7% in PvP. Players many levels below their target will always have at least a 1% chance of landing a spell. This means you will have the minimum chance of hit against PvE targets at least 11 levels higher than you, and PvP targets at least 16 levels higher. For most casters, 1% of additional spell hit amounts to 1% additional damage in the long run. Increasing spell hit Chance to hit can be increased by talents or gear with spell hit rating up to a cap of 99%. Spell hit rating is a stat found on gear that increases spell hit chance by a certain percent per point, based on level. At level 70, 12.6 spell hit rating is equivalent to 1% spell hit. Because the highest level mob currently present is level 73 (all BC raid bosses, for instance), a level 70 caster has an effective spell hit rating cap of 202, assuming no other spell hit sources. Aside from gear with spell hit rating, chance to hit can also be increased through some buffs and spells. Draenei casters give an additional 1% spell hit to their group with Inspiring Presence. The following table lists some talents that also increase a caster's chance to hit with spells. Taking these effects into consideration lowers the effective spell hit rating cap. Talents and gear combined, chance to hit with spells cannot exceed 99%. Casters should keep this cap in mind when considering their gear. In PvP at level 70, anything more than +3% chance to hit is excessive. For PvE raiding, bosses are considered to be 3 levels higher than the caster, meaning +16% is the most that will be effective. Note that some classes (for example Paladins and Rogues) can spec to gain extra chance to have spells miss them. Also, some abilities (e.g. - Cloak of Shadows) gives the player using the ability extra chance to have spells miss as well. Extra spell hit does in fact mitigate this extra chance to hit, but is otherwise useless. Effect of resistance Spell resistance has a separate effect that is considered in addition to spell hit chance, and is based on a resistance stat for a specific school. In general a certain amount of resistance will mitigate a certain percentage of damage from a magic school. For binary spells that do not partially resist, the resistance mitigation is combined with the spell hit chance to give an overall percentage for the spell to land or be resisted. The chance to hit is multiplied by the mitigation factor from the resistance to give an overall chance to hit. For the following formula, B is base chance to hit with spells, H is increased chance to hit from gear and talents, and R is the mitigation factor given from resistance. (B + H) * R For example, a caster with 6% increased chance to hit, attacking a mob 3 levels higher (83% base chance) that has enough resistance to mitigate 50% of spell damage, the overall chance to hit with a binary spell is 44.5% (83% + 6%) * 50% = 44.5% For non-binary spells, resistance is computed as a second calculation after the spell hit chance is rolled. After a spell hit is determined, a partial resist calculation based on resistance is done, which can also result in a full resist. These two resists appear identically in the combat log, and there is no known way to distinguish a spell miss from a full resist. The effect of crit on hit chance Unlike the melee combat system, spell crit makes absolutely no difference to hit chance. All spells, regardless of whether they are treated as binary or not, roll hit and crit separately. Conceptually, the game rolls for your hit chance first, and if the spell hits you have a separate roll for whether it crits. Overall chance to crit over all spells cast is thus affected by hit rate. To calculate overall crit rate, multiplying the two chances together: crit rate over all spells = crit * hit For example, a caster with no spell hit rating gear or talents, against a mob 3 levels higher (83% hit chance), and 30% crit rating from gear and talents: crit rate over all spells = 30% * 83% = 24.9% In addition, direct damage spells suffer from partial resistance, but again, that has no effect on whether a spell hits or not. A fully resisted spell due to spell school resistance is indistinguishable from a spell which didn't hit, which contributes to some of the confusion on the matter. Spell hit rating caps for level 70 A common question among casters is how much spell hit rating is needed to hit the 99% chance to hit cap. As stated earlier, this depends on the level of the targets one expects to encounter, and any talents that add chance to hit with spells. The following table summarizes how much spell hit rating is needed for a certain level, after all talents and buffs are taken into consideration. To use the table, first add up how much spell hit you already have (don't forget the possibility of a Draenei or a shaman with Totem of Wrath in your group), then look up that row to find the hit rating cap for targets level 70 up to 73. Notes Binary spells are any spells that have a non-damage effect. (examples: Psychic Scream, Polymorph, Curse of Recklessness) Non-binary spells are spells that do only damage (example: Mind Blast). See also Formulas:Magical resistance. Binary spells always either hit or are resisted completely. If they are DOTs they may be also subject to Magical Resistance, affecting the damage from each tick of the DOT. See also *Resistance References Category:Formulas and Game Mechanics Category:Attributes